DPRG mailing list archives: [DPRG] RBNO Today WEDNESDAY DEC 26

Fri Dec 28 14:38:52 CST 2007

Ah, sorry, meant for all on DPRG, so you can read as well.

I wanted to get some more of those frightened grasshopper kits,
and do a cataraman myself. I thought I'd mount them side by
side, and out rig two motors. Also, by crossing motors and
angling the solar cells outward, or by not cross them and
angling the cells in toward each other, I thought I could make a
photovore, which would turn toward the light. Given a bright
spot, it would keep the robot moving inside the beam, turning
when it got to the edge of the spot.

But until I try it, it's only a theory. 

On the other hand, wouldn't this be a comeupance on the
2-transistor and 1-transistor robots taken to a new extreme? In
fact, with the cells pointed down at a reflective surface, and a
black line, I think we could make a 0-transistor line follower.
Maybe not, I vaguley recall someone came up with a 1-photo cell
line follower.

Randy
www.newmicros.com

  _____  

From: Jeff Koenig [mailto:koenig.jeff at gmail.com] 
Sent: Friday, December 28, 2007 1:48 PM
To: rmd at newmicros.com
Subject: Re: [DPRG] RBNO Today WEDNESDAY DEC 26

Hi Randy,

(If you want, you can post my reply to the group.  I saw that
your message was sent only to me.)

Well, the two toothbrushes were mounted a few inches from each
other on a piece of foam core, pontoon boat style, so it would
never tip over. 

It buzzed around in a circular path.  Ed and Eric trimmed the
bristles on each brush so that they were at quite an angle, so
the robot "tipped" forward. This made it go forward very
quickly, but probably not as fast as yours. 

Only one motor was used.  Actually, three brushes were used, as
Ed made a standard one-brush bristlebot, then mounted two
brushes to a separate piece of foam core.  He then lashed the
single bristlebot to the two-brush assembly. 

His single brush bristlebot had a two longish pieces of copper
wire so he could bend stabilizing "legs".  It was wondered
whether two motors could be used for differential-esque
steering.  If I get some spare time this afternoon, I'm going to
try to throw one together. 

Thanks for the suggestion!  We had a lot of fun, and hopefully
we'll have more built with the motors I handed out.

Best Regards,
Jeff

On Dec 28, 2007 1:41 PM, Randy M. Dumse < rmd at newmicros.com>
wrote:

How much did the second toothbrush improve stability? Did it
maintain a constant course that way? (I would suppose not, but
possibly more so than a single.) Did he use multiple motors? or
just one for the two?

Randy

  _____  

From: dprglist-bounces at dprg.org
[mailto:dprglist-bounces at dprg.org] On Behalf Of Jeff Koenig

Sent: Friday, December 28, 2007 11:13 AM 

To: dprglist at dprg.org
Subject: Re: [DPRG] RBNO Today WEDNESDAY DEC 26

Who knew that BristleBots could be so much fun?  Ed put one
together at Tuesday's RBNO with two toothbrushes and some
outrigger wires that scooted about quite nicely.

-Jeff

On Dec 26, 2007 12:34 PM, Jeff Koenig <koenig.jeff at gmail.com>
wrote:

I'll be there.  I've got pager motors to give away to the first
25 attendees, so bring your cut-down toothbrush, some
double-stick tape, wire, and a small battery if you'd like to
build a Scrub Bot tonight.

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